Hand operated crimping tools for crimping a terminal onto a conductor generally include a frame, a pair of pliers-like handles, and a mechanical linkage. A pair of mating crimping dies is included, one die being coupled to each handle so that upon operation of the handles the two dies are brought into mating engagement for effecting the desired crimped termination. Such a hand tool is disclosed in U.S. Pat. No. 4,829,805 which issued May 16, 1989 to Koehn. In some variations of this structure one of the handles is fixed to the frame so that, upon operation of the handles, only the die coupled to the other handle is pivoted into engagement with the die coupled to the frame. Such hand tools are disclosed in U.S. Pat. Nos. 5,307,553 which issued May 3, 1994 to Frohlich: 5,168,743 which issued Dec. 8, 1992 to Schrader et al.; 5,012,666 which issued May 7, 1991 to Chen et al.; and 4,614,107 which issued Sep. 30, 1986 to Norin. Typically, the mechanical linkage of these tools utilizes a drive link pivotally attached to the frame and the movable handle, with the handle being pivotally attached to a pivoting jaw which carries the movable die into engagement with a fixed die attached to the frame. A serrated surface on a side of the drive link engages a pawl pivotally attached to the movable handle for compelling full movement of the handle once the crimping operation is started. This linkage structure has the advantage of being simple to manufacture and maintain and is very effective and efficient to operate. However, such hand tools are limited to pivotal movement of the two mating dies during the crimping operation. This pivotal movement causes a slight rolling of the terminal as the mating dies crimp the terminal barrel causing distortion of the final crimped termination profile. Linear movement of the two mating dies is more desirable because this rolling action is not present. However, hand tools that utilize mechanisms that support linear movement of the mating crimping dies usually incorporate a C-shaped frame structure that is required to be relatively massive to prevent deflection during the crimping operation. See, for example, U.S. Pat. Nos. 3,322,008 which issued May 30, 1967 to Filia and 5,042,286 which issued Aug. 27, 1991 to Wiebe et al. Necessarily these structures utilize a linkage structure that is different, and frequently more complex, than the more desirable linkage structure of the pivoting hand tools mentioned above.
What is needed is a crimping hand tool that utilizes the toggle type actuating mechanism of the pivoting tools but moves the mating dies together along a linear path during the crimping operation, while providing a frame that is relatively small and light weight but sufficiently strong to prevent significant deflection during the crimping operation.